Thin wall polyether block amide membrane tubing and module

ABSTRACT

Composite membrane tubing includes a porous scaffold support combined with polyether block amide copolymer. The composite membrane tubing has overlapping “fusion areas” that are an artifact of the manufacturing process. The methods of manufacturing above-mentioned composite membrane tubing have also been addressed. The composite membrane tubing can be reinforced with a structural mesh to further provide rigidity and strength. Composite membrane tubing or generally extruded tubing can be integrated into a multi-tube module for various applications.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. provisionalpatent application No. 62/846,034, filed on May 10, 2019, and to U.S.provisional patent application No. 62/846,030, filed on May 10, 2019;the entirety of both applications are hereby incorporated by referenceherein.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a composite membrane tubing system andtheir integration into pervaporation or heat/mass exchange systems suchas drying or humidifying gases, purification, medical, analytical, HVACand oil & gas applications. The process for manufacturingabove-mentioned tubular systems is provided.

Background

Polyether block amides (PEBAs) are a family of high performance blockcopolymers consisting of soft polyether (PE) blocks and rigid polyamide(PA) blocks marketed under the PEBAX® and VESTAMID® brands by Arkema Incand EVONIK Resource Efficiency Gmbh, respectively. Arkema firstcommercialized PEBAX® thermoplastic elastomers in 1981 as part of aninitiative to develop “soft” nylon materials. PEBAX® has the generalformula of: HO-(CO-PA-CO-O-PE-O)_(n)-H.

PA block is in a rigid semi-crystalline phase, which contributes to highend mechanical properties and can be optionally bio-based from 28 to97%, according to ASTM D6866. While PE block has very low glasstransition temperature, about −60° C. which provides outstandingproperties at low temperature. In addition, PE block can be tuned tohydrophobic or hydrophilic.

PEBA is a high-performance thermoplastic elastomer with these followingcharacteristics: resistance against a wide range of chemicals, lowdensity among thermoplastic elastomers, superior mechanical and dynamicproperties including, flexibility, impact resistance, energy return,fatigue resistance, and these properties are maintained at lowtemperature, such as lower than −40° C. PEBA is used in medical productssuch as catheters for its flexibility, its good mechanical properties atlow and high temperatures, and its softness.

It is also widely used in the manufacture of electric and electronicgoods such as cables and wire coatings, electronic device casings,components, etc. PEBA can be used to make textiles as well as breathablefilm, fresh feeling fibers or non-woven fabrics. These compounds willfind various applications in sports, optical, and electronics, wheretoughness and lightness are crucial. Some hydrophilic grades of PEBA arealso used for their anti-static and anti-dust properties. Since nochemical additives are required to achieve these properties, productscan be recycled at end of life.

Because of its unique copolymer structure, hydrophilic PEBA films offera combination of mechanical strength, and ease of processing. Unlikemicroporous products, the monolithic structure of these PEBA films are abarrier to liquid water and bacteria and exhibit a high moisture vaportransmission rate (MVTR). Each of these advantages make PEBA filmsbreathable. This material is ideal for many applications such asconstruction house-wrap films, breathable textiles for sports,packaging, and selective membranes.

To achieve even higher MVTR, PEBA films need to be very thin. However,thinner films demonstrate poor mechanical strength and dimensionalstability. Traditionally, to date, thicker membranes are produced.Thicker membranes have high transmission resistance, and lowerpervaporation performance. In fact, breathable PEBA films are generallymelt extruded into a thin monolithic film above 25 microns, which limitstheir application.

SUMMARY OF THE INVENTION

The invention is related to ultra-thin composite PEBA tubes made fromelastomeric polyether block amide (PEBA), preferably ultra-thincomposite PEBA membranes and modules comprising these composite tubes.In an exemplary embodiment, a porous scaffold support, such as a porouspolymeric material or membrane, is combined with PEBA to enable thereinforced composite membrane to be ultra-thin, wherein the wallthickness of the composite PEBA tube is less than 50 μm, and preferablyless than 25 μm and more preferably less than 10 μm and even morepreferably less than 5 μm. An ultra-thin composite PEBA film may be madeinto a PEBA pervaporation tube by wrapping a composite PEBA film andbonding or attaching the overlap areas. A composite PEBA tube can bemade by spirally wrapping or longitudinally wrapping a composite PEBAfilm or wrapping a porous scaffold support around an ultra-thin walledextruded PEBA tube. A mandrel may be used for wrapping the compositePEBA film thereon. These thin composite PEBA tubes, may be used aspervaporation tubes that can be incorporated into a pervaporationmodule. The wrapped composite PEBA pervaporation tube may have fusedareas wherein at least a portion of the overlap area is fused together.

The porous scaffold support may include a porous material and the PEBAmay be coated thereon and may fill, at least partially the pores of theporous material or membrane. An exemplary porous scaffold supportmaterial is a porous polymer material of polyethylene or polypropylene,and may be a porous fluoropolymer material or membrane, such as anexpanded fluoropolymer. An exemplary expanded fluoropolymer is expandedpolytetrafluoroethylene (PTFE). An exemplary porous scaffold supportmaterial has a thickness that is less than about 25 microns, less thanabout 20 microns, less than about 10 microns and more preferably lessthan about 5 microns. A thin porous material is preferred as it willallow for higher rates of moisture transfer through the composite PEBAtube. A porous scaffold support, such as an expanded fluoropolymer orporous polyethylene or polypropylene, may have very small pores, whereinthe average pores size is no more than about 10 microns, no more thanabout 5 microns, no more than about 1 micron, no more than about 0.5microns and any range between and including the values provided. Theaverage pore size can be determined use a coulter porometer, wherein theMinimum Pore Size is defined at the point where the wet curve meets thedry curve. The Mean Pore Size is defined as the point at which theamount of flow through the sample on the wet curve is exactly 50 percentof the amount of flow at the same pressure when the sample is dry. Asmall average pore size may be desirable to enable PEBA to imbibe intothe pores of the porous scaffold material. The smaller the pore size thegreater the capillary forces to pull the solution or melted PEBAtherein.

The PEBA may be attached to the porous scaffold support by melt casting,wherein the PEBA is melted onto the porous scaffold support. The twolayers may then be compresses to force the melted PEBA into the pores ofthe porous scaffold support. PEBA may also be solution cast onto or intothe pores of a porous scaffold support. The PEBA may be dissolved in asolvent and the cast onto the porous scaffold support, wherein it maywick into the pores and substantially fill the pores to make anon-permeable composite film. In flat sheet assemblies, such as a ventor plate and frame pervaporation modules, it may be desirable to haveminimal PEBA integration into the pores of the porous scaffold supportand therefore melt casting may be preferred with little interpenetrationof the PEBA into the pores. It is also possible to achieve a compositestructure with minimal penetration by solution casting and tuning thesolvent system to evaporate before the PEBA is able to penetrate thepore structure fully.

A composite PEBA film comprising the PEBA polymer and the porousscaffold support may be substantially non-porous, wherein the pores ofthe porous scaffold support are filled or blocked by the PEBA polymersuch that the composite PEBA film has a Gurley densometer reading ofabout 100 seconds or more, and preferably 200 second or more; using aGurley Densometer 4340 automatic densometer, from Gurley PrecisionInstruments, Troy N.Y.

The composite PEBA film may be wrapped to form a tube and may includeoverlap areas that are fused together. These overlap areas will be atleast twice as thick as the composite PEBA film and therefore it may bedesirable to keep the overlap area to a minimum percentage of the outersurface area of the composite PEBA tube, such as no more than about 30%,no more than about 25%, no more than about 20%, no more than about 10%,or even no more than about 5% outside surface area of the tube.

According to one embodiment of the present invention, there is provideda tubular structure made from a composite film of a porous scaffoldsupport and PEBA copolymer. The tubular structures have overlappingfused areas.

According to one embodiment of the present invention, there is provideda process for the preparation of the composite membrane tubing bytape-wrapping a porous scaffold support around a mandrel. The mandrel isthen passed through a heating chamber or an infrared chamber to fuse thewrapped tape into a continuous tubular structure. The tubular structureis then passed through a coating process wherein the membrane tube iscoated with the PEBA copolymer. The assembly is then passed throughheating chamber to dry the PEBA pervaporation tube. Then the tube isdipped in a swelling agent, such as water or a solvent, and removed fromthe mandrel. It may be necessary to provide internal pressure to thetube assembly to remove the PEBA tube from the mandrel.

According to one embodiment of the present invention, there is provideda process for the preparation of tubular structure adapted topervaporate the fluid by spirally or longitudinally, also referred to ascigarette, wrapping one or more membranes around mandrel and using heator infrared radiation on the assembly to fuse the wrapped membrane tapesinto a continuous cylindrical tube. Then the tube is dipped in aswelling agent, such as water or a solvent, and removed from themandrel. It may be necessary to provide internal pressure to the tubeassembly to remove the PEBA tube from the mandrel. Note that anultrasonic instrument, such as an ultrasonic welder, having anultrasonic horn and anvil, such as a those available from BransonUltrasonics Corp, Rochester N.Y., may be used to create very localizedheat between the overlapped layers of the wrapped tube to fuse thelayers together.

An alternative embodiment of the present invention involves extrudingtubes to a very thin cross-sectional thickness and optionallyreinforcing with a reinforcement after extrusion, such as by tapewrapping.

An exemplary PEBA composite film may include a biocide to prevent theformation of mold in a pervaporation module, as this is an idealenvironment for mold to form. A biocide may be configured in the PEBApolymer, as a coating on the porous scaffold support, as a coating onthe final PEBA layer, or a combination thereof. Any suitable biocide maybe used and the concentration may be adjusted according to the useconditions.

According to one embodiment of the present invention, a tubereinforcement may be configured around the outside and/or inside of acomposite PEBA tube to provide additional structural support and maycomprise a structural mesh. A structural mesh may be configured aroundthe PEBA tube(s) to provide additional structural rigidity. Thestructural mesh may comprise a plastic or metal material depending onthe degree of reinforcement required. The metal may also be used toenhance heat transfer to the tubular structure to enhance pervaporation.The structural mesh may be secured on the ends of the tubular structureusing an adhesive or a heat shrinking material, or a combination of thetwo.

According to one embodiment of the present invention, a method forputting fittings at the ends of the tubes is provided. The fittings maybe coupled to the composite PEBA tube by inserting a rigid plastictubing at the ends of the PEBA tubing, and inserting into the plastictubing different kinds of fittings such as compression, barbed,push-to-connect, etc. The assembly may be secured on the ends of thetubular structure using an adhesive or a heat shrinking material, or acombination of the two. Alternatively, tubes, with or without fittings,are inserted into a setting compound, or potted, into a tube sheet orheader.

The manufacturing processes described above ensure that the tubes aremuch thinner than those described in the prior art. The thinness of thetubes along with the inherent nature of the material ensures tubes whichpermeate water, water vapor or a polar species to transmit across thetube wall at higher rates and lower cost.

According to one embodiments of the present invention, there areprovided devices such as modules that employ pervaporative tubing to dryincoming air streams for medical, analytical, electrochemical and oil &gas purposes. Several pervaporative tubes are forced into a cylindricalstructure which constitutes the “shell”. The pervaporative tubes arecapped off and then dipped into potting resin. Once, the potting resinand seals all tubes in place, the process is repeated on the other endof the tubes. Finally, the ends are capped off with front and rearheaders.

Ultra-thin PEBA composite membranes can be used to make tubes. Thesetubes are very strong, and therefore can take high pressure feed.

Because of the strength and thinness, there is less resistance topermeation and therefore higher performance systems.

Because of the ultra-thin structure, less material, both PEBA and porousscaffold support, are used to produce these tubes, therefore the unitshave inherently lower cost, and therefore the technology can be appliedto wider range of applications beyond the current thick walled extrudedtubes that are state-of-art in the market.

The pervaporation modules and pervaporation tubes comprising a PEBAcopolymer and preferably an ultra-thin composite PEBA film are ideallysuited for desalination, ionic liquid desiccation, waste processing,heat exchange, mass exchange and numerous other applications.

The desired ultra-thin composite PEBA tubing will also have thefollowing merits: high dimensional stability; high moisture vaportransmission rate; lightweight; excellent toughness and tear resistance;easy for processing in a roll to roll scale up; low cost; anti-dust;recyclable; excellent virus and bacteria barrier; excellent liquid &odor barrier and hygienic.

The desired ultra-thin reinforced composite PEBA film should have thefollowing features: no curl, easy to handle; good dimensional stability;high MVTR; lightweight; excellent toughness and tear resistance; easy toprocess in high volume, such as a roll to roll system; low cost;recyclable; flexible; act as an excellent virus and bacteria barrier;and be an excellent liquid & odor barrier and be hygienic.

Example 1

In one embodiment, an ultra-thin reinforced composite PEBA film isprepared by dissolving the PEBA, MV1074 from Arkema Inc., inethanol/toluene (50 wt %: 50 wt % mix) at a 15% weight ratio. Themixture was stirred at 60° C. until homogenous and translucent. The PEBApolymer solution was then applied to a microporouspolytetrafluoroethylene material which is tensioned around achemically-resistant plastic frame. The polymer solution was then pouredon to the microporous scaffold. The membrane was dried at roomtemperature. The final thickness of the membrane was 5 microns.

Example 2

In another embodiment, an ultra-thin reinforced composite PEBA film isprepared by dissolving the PEBA MH1657 polymer from Arkema Inc., inethanol and water at a 20% weight ratio. The mixture was stirred untilhomogenous and translucent. The PEBAX® MH1657 polymer was then appliedto a microporous polyethylene material using a doctor blade. Themembrane was dried at room temperature for 8 hours. The membrane wasthen annealed in the oven for 5 minutes at 80° C. The final thickness ofthe membrane was 5 microns.

Example 3

In another embodiment, an ultra-thin reinforced composite PEBA/PFSA filmis prepared by dissolving the 1.6 g PEBA polymer from Arkema Inc. and0.4 g PerfluoroSulfonicAcid, (PFSA) in ethanol and water at a 20% weightratio i.e. 2 grams of total polymer to 8 grams of solvent. The mixturewas stirred until homogenous and translucent. The PEBA/PFSA blendpolymer was then applied to a microporous polyethylene material with adoctor blade. The film was dried at room temperature for 24 hours. Thefinal thickness of the film was 15 microns.

It will be apparent to those embodiments mentioned above can be scaledup to a roll-to-roll, continuous process.

Example 4

In another embodiment, an ultra-thin reinforced composite PEBA film isprepared by melt lamination of PEBA, MH1657 at about 20 micron ontoexpanded polytetrafluoroethylene (ePTFE) support scaffold materials.MH1657 was hot pressed with ePTFE at 200° C. for 90 seconds. The filmwas 7 micron and transparent.

The summary of the invention is provided as a general introduction tosome of the embodiments of the invention and is not intended to belimiting. Additional example embodiments including variations andalternative configurations of the invention are provided herein.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description explain the principles of the invention.

FIG. 1 shows cross-sectional view of an exemplary porous scaffoldsupport having a porous structure and pores therein, wherein the PEBAsubstantially fills the pores of the scaffold support.

FIG. 2 show a cross-sectional view of an exemplary ultra-thin compositePEBA film having a layer of PEBA on either side of the porous scaffoldsupport.

FIG. 3 shows cross-sectional view of an exemplary ultra-thin compositePEBA film formed by imbibing PEBA copolymer into a porous scaffoldsupport using solution casting process, wherein the PEBA substantiallyfills the pores of the scaffold support.

FIG. 4 shows a cross-sectional view of a composite PEBA film having abutter-coat layer of PEBA on the surface of a porous scaffold support.

FIG. 5 shows a cross-sectional view of an overlap region of a compositePEBA tube having two layers of composite PEBA film.

FIG. 6 shows a perspective view of an exemplary PEBA tube that is aspirally wrapped PEBA tube comprising a spirally wrapped composite PEBAfilm having overlap areas that are attached form a spiral wrapped PEBAtube.

FIG. 7 shows a perspective view of an exemplary PEBA tube that is alongitudinally wrapped PEBA tube comprising a spirally wrapped compositePEBA film having overlap areas that are attached form said cigarettewrapped PEBA tube.

FIG. 8 shows pervaporation module compromising a plurality of compositePEBA pervaporation tubes.

Corresponding reference characters indicate corresponding partsthroughout the several views of the figures. The figures represent anillustration of some of the embodiments of the present invention and arenot to be construed as limiting the scope of the invention in anymanner. Further, the figures are not necessarily to scale, some featuresmay be exaggerated to show details of components. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Also, use of “a” or “an” are employed to describeelements and components described herein. This is done merely forconvenience and to give a general sense of the scope of the invention.This description should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Certain exemplary embodiments of the present invention are describedherein and are illustrated in the accompanying figures. The embodimentsdescribed are only for purposes of illustrating the present inventionand should not be interpreted as limiting the scope of the invention.Other embodiments of the invention, and certain modifications,combinations and improvements of the described embodiments, will occurto those skilled in the art and all such alternate embodiments,combinations, modifications, improvements are within the scope of thepresent invention.

As shown in FIG. 1, an exemplary an ultra-thin porous scaffold support10 is a thin sheet or porous membrane having a top side 12, bottom side14 and pores 16 therethrough from the top to the bottom. An exemplaryporous scaffold support is a planar sheet of material having a thicknessof less than 50 microns, and preferably less than 25 microns, asdescribed herein.

As shown in FIG. 2, an exemplary ultra-thin composite PEBA film 40 hasPEBA polymer 30 imbibed into the pores 16 of the porous scaffold support10. This may be accomplished by melt laminating and pressing PEBA resininto the pores of the porous scaffold material, or through solutioncasting or imbibing. The composite PEBA film has a top surface 42 and abottom surface 44 and a thickness 43 therebetween. The thickness of thecomposite PEBA film is preferably less than 50 microns, more preferablyless than 25 microns and even more preferably less than 10 or 5 microns.There is a PEBA butter coat layer 48, 48′ extending across the top andbottom surfaces, respectively. A butter coat layer is a think layer ofthe PEBA copolymer extending over the porous scaffold support. Abutter-coat layer may be on one or both surfaces of the composite PEBAfilm.

As shown in FIG. 3, an exemplary ultra-thin composite PEBA film 40 hasPEBA polymer 30 imbibed into the pores 16 of the porous scaffold support10. This may be accomplished by melt laminating and pressing PEBA resininto the pores of the porous scaffold material, or through solutioncasting or imbibing. In this embodiment, there is no butter-coat layer.

As shown in FIG. 4, a composite PEBA film 40 has a butter-coat layer 48of PEBA copolymer 30 on the top side 12 or surface of a porous scaffoldsupport 10. This thin composite PEBA film may be used in a flat sheet ina pervaporation module or in a humidification vent application to allowhumidity to pass therethrough but to exclude other contaminants orparticles from entering an enclosure. As shown in FIG. 4, a flat sheetof a composite PEBA film may be made for plate and frame configurations.IT may be preferable to use this single sided butter-coat layercomposite PEBA film for these applications as the PEBA may be very thin,such as less than 10 microns or even more preferably less than 5microns.

FIG. 5 shows a cross-sectional view of an overlap area 58 of a compositePEBA tube having two layers of composite PEBA film 40 and 40′. Theoverlap area is fused together along the fused interface 20 which mayinclude PEBA from one butter-coat layer melting into the PEBA of theadjacent butter-coat layer. Note that PEBA from one composite PEBA filmmay melt into the pores or other PEBA polymer in an adjacent compositePEBA film. The thickness of the overlap area 58 or layers 23 is greaterthan the thickness of a single composite PEBA film, and thereforereducing the overlap area is important to increase throughput andpermeation rates through the tube.

As shown in FIG. 6, a composite PEBA tube 50 is a spirally wrapped PEBAtube 60 having a composite PEBA film 40 spirally wrapped to form theouter wall 52 and conduit 51 of the spirally wrapped PEBA tube. Thespirally wrapped PEBA tube has overlap areas 58 that spiral around thetube. The composite PEBA film that may be attached or bonded to eachother to form bonded area 59. The bonding may be formed by fusing thelayers together, wherein the PEBA from one layer is intermingled withthe PEBA of the second, or overlapped layer. This bonding may beaccomplished through heat, such as by fusing or by the addition of asolvent that enables intermingling of the polymers. The composite PEBAtube 50 has a length 55 from an inlet 54 to an outlet 56 and a lengthaxis 57 extending along the center of the tube. A first layer of thecomposite PEBA film is bonded to the PEBA polymer of a second layer ofthe composite PEBA film to form the bonded area. As described herein,the overlap width may be fraction of the tape width, such as no morethan about 30% of the tape width, no more than about 25% of the tapewidth, no more than about 20% of the tape width, no more than about 10%of the tape width, or even no more than about 5% of the tape width toprovide a high percentage of the spiral wrapped tube that is only asingle layer, thereby increase the rate of transfer of ions through thetube and also reduce the total usage of film thus lower cost.

As shown in FIG. 7, a composite PEBA tube 50 is a longitudinally wrappedPEBA tube 70 having a composite PEBA film 40 longitudinally wrapped toform the longitudinally wrapped PEBA tube and tube conduit 51. Thelongitudinally wrapped PEBA tube has an overlap area 58 of the compositePEBA film that extends down along the length 55 or length axis 57 of thetube. The length extends from the inlet 54 to the outlet 56. The overlaparea may be attached or bonded to each other to form a fused area 59wherein the layers of the composite PEBA film are bonded or fusedtogether, wherein the PEBA from one layer is intermingled with the PEBAof a second layer through melting or solvent bonding. The bonding may beformed by fusing the layers together, wherein the PEBA from one layer isintermingled with the PEBA of the second, or overlapped layer. Thisbonding may be accomplished through heat, such as by fusing or by theaddition of a solvent that enables intermingling of the polymers. Anexemplary composite PEBA pervaporation tube comprises a longitudinallywrapped, or “cigarette wrapped” composite PEBA film sheet to form alongitudinal wrapped PEBA pervaporation tube. The composite PEBA film iswrapped around the longitudinal axis of the tube. In this embodiment thelength of the tube is the width of the composite PEBA membrane, and thewrap angle is perpendicular to the longitudinal axis. The longitudinalwrapped PEBA membrane has an overlap area having an overlap width.Again, the overlap width may be no more than about 30% of the tapewidth, no more than about 25% of the tape width, no more than about 20%of the tape width, no more than about 10% of the tape width, or even nomore than about 5% of the tape width to provide a high percentage of thespiral wrapped tube that is only a single layer, thereby increase therate of permeation and transfer of ions through the tube.

FIG. 8 shows a pervaporation module 80 comprises a plurality of PEBApervaporation tubes 82 that are composite PEBA pervaporation tubes 84.Each of the tubes is coupled to an inlet tube sheet 85 and outlet tubesheet 89. A flow of water flows through the plurality of tubes from theinlet 54 to the outlet 56 of the tube. An airflow 87 passes over thetubes to pull away moisture. The inlet relative humidity 86 may be muchlower than the outlet relative humidity 88. Each of the composite PEBAtubes may further comprise a tube support 90, which is an additionalsupport structure or tube that extends around the composite PEBA tubesto prevent expansion of the composite PEBA tubes under pressure. Thewater flowing through the tubes may be pressurized to increasepermeation therethrough and a tube support may prevent diameter creep orswelling. A tube support may be a net or screen that is resistant toradial forces that would increase the diameter and may be made of rigidpolymer material and/or a metal, such as a porous metal tube including,but not limited to a, perforated metal tube or woven metal tube.

It will be apparent to those skilled in the art that variousmodifications, combinations and variations can be made in the presentinvention without departing from the scope of the invention. Specificembodiments, features and elements described herein may be modified,and/or combined in any suitable manner. Thus, it is intended that thepresent invention cover the modifications, combinations and variationsof this invention provided they come within the scope of the appendedclaims and their equivalents.

What is claimed is:
 1. An ultra-thin composite PEBA tube comprising: a)a composite PEBA film comprising: i) a porous scaffold support; and ii)a PEBA copolymer attached to the porous scaffold support; iii) athickness of no more than 50 microns; b) an overlap area of thecomposite PEBA film that is fused to form said PEBA tube; c) an inlet;d) an outlet; e) a length from said inlet to said outlet.
 2. Theultra-thin composite PEBA tube of claim 1, wherein the composite PEBAfilm thickness is no more than 25 microns.
 3. The ultra-thin compositePEBA tube of claim 1 wherein the composite PEBA film thickness is nomore than 10 microns
 4. The ultra-thin composite PEBA tube of claim 1,wherein the composite PEBA film thickness is no more than 5 microns 5.The ultra-thin composite PEBA tube of claim 1, wherein the overlap areais no more than 30% of an outside surface area of the composite PEBAtube.
 6. The ultra-thin composite PEBA tube of claim 1, wherein theoverlap area is no more than 20% of an outside surface area of thecomposite PEBA tube.
 7. The ultra-thin composite PEBA tube of claim 1,wherein the overlap area is no more than 10% of an outside surface areaof the composite PEBA tube.
 8. The ultra-thin composite PEBA tube ofclaim 1, wherein the composite PEBA film is spirally wrapped to formsaid composite PEBA tube.
 9. The ultra-thin composite PEBA tube of claim1, wherein the composite PEBA film is longitudinally wrapped to formsaid composite PEBA tube
 10. The ultra-thin composite PEBA tube of claim1, wherein the porous scaffold support is expandedpolytetrafluoroethylene membrane.
 11. The ultra-thin composite PEBA tubeof claim 1, wherein the porous scaffold support comprises a porouspolyethylene membrane.
 12. The ultra-thin composite PEBA tube of claim1, wherein the porous scaffold support comprises a porous polypropylenemembrane.
 13. The ultra-thin composite PEBA tube of claim 1, furthercomprising a biocide to prevent mold formation.
 14. An ultra-thincomposite PEBA tube comprising: a) a PEBA tube; b) a porous scaffoldsupport attached to an outer surface of the PEBA tube; and c) an inlet;d) an outlet; e) a length from said inlet to said outlet.
 15. Theultra-thin composite PEBA tube of claim 13, wherein the porous scaffoldsupport is spirally wrapped around the PEBA tube.
 16. The ultra-thincomposite PEBA tube of claim 13, wherein the porous scaffold support islongitudinally wrapped around the PEBA tube.
 17. A pervaporation modulecomprising: a) an ultra-thin composite PEBA tube comprising: i)composite PEBA film comprising: a porous scaffold support; and a PEBAcopolymer attached to the porous scaffold support; a thickness of nomore than 50 microns; ii) an overlap area of the composite PEBA filmthat is fused to form said PEBA tube; iii) an inlet; iv) an outlet; b)an inlet tube sheet sealed to the inlet of the composite PEBA tube; c)an outlet tube sheet sealed to the outlet of the composite PEBA tube; d)a flow of water through the composite PEBA tube from the inlet tubesheet to the outlet tube sheet; e) a flow of fluid over the ultra-thincomposite PEBA tube; wherein water vapor passes through the compositePEBA tube and into the flow of fluid thereover to increase the relativehumidity of the flow of fluid.
 18. The pervaporation module of claim 17,comprising a plurality of composite PEBA tube comprising coupled to theinlet and outlet tube sheets.
 19. The pervaporation module of claim 17,wherein the composite PEBA film comprises a biocide.
 20. Thepervaporation module of claim 17, further comprising a tube supportconfigured around the ultra-thin composite PEBA tube.